To date, seven distinct DUB families have been described in humans, i.e., the ubiquitin-specific proteases (USPs), the ovarian tumor (OTU) proteases, the Machado-Joseph Disease (MJD) DUBs, the ubiquitin C-terminal hydrolases (UCHs), the motif interacting with ubiquitin (MIU)-containing novel DUB family (MINDY), the JAB1/MPN/MOV34 metalloprotease DUBs (JAMMs), and the recently discovered zinc finger-containing ubiquitin peptidase 1 (ZUP1) [10]. Here, ZUP1 is linked to Machado-Joseph disease.